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comparison: src/ucx/cx/allocator.h

src/ucx/cx/allocator.h

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1 /*
2 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
3 *
4 * Copyright 2021 Mike Becker, Olaf Wintermann All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions are met:
8 *
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 *
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 *
16 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
17 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
18 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
19 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
20 * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
21 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
22 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
23 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
24 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
25 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
26 * POSSIBILITY OF SUCH DAMAGE.
27 */
28 /**
29 * \file allocator.h
30 * Interface for custom allocators.
31 */
32
33 #ifndef UCX_ALLOCATOR_H
34 #define UCX_ALLOCATOR_H
35
36 #include "common.h"
37
38 #ifdef __cplusplus
39 extern "C" {
40 #endif
41
42 /**
43 * The class definition for an allocator.
44 */
45 typedef struct {
46 /**
47 * The allocator's malloc() implementation.
48 */
49 void *(*malloc)(
50 void *data,
51 size_t n
52 );
53
54 /**
55 * The allocator's realloc() implementation.
56 */
57 void *(*realloc)(
58 void *data,
59 void *mem,
60 size_t n
61 )
62 __attribute__((__warn_unused_result__));
63
64 /**
65 * The allocator's calloc() implementation.
66 */
67 void *(*calloc)(
68 void *data,
69 size_t nelem,
70 size_t n
71 );
72
73 /**
74 * The allocator's free() implementation.
75 */
76 void (*free)(
77 void *data,
78 void *mem
79 )
80 __attribute__((__nonnull__));
81 } cx_allocator_class;
82
83 /**
84 * Structure holding the data for an allocator.
85 */
86 struct cx_allocator_s {
87 /**
88 * A pointer to the instance of the allocator class.
89 */
90 cx_allocator_class *cl;
91 /**
92 * A pointer to the data this allocator uses.
93 */
94 void *data;
95 };
96
97 /**
98 * High-Level type alias for the allocator type.
99 */
100 typedef struct cx_allocator_s CxAllocator;
101
102 /**
103 * A default allocator using standard library malloc() etc.
104 */
105 extern CxAllocator *cxDefaultAllocator;
106
107 /**
108 * Function pointer type for destructor functions.
109 *
110 * A destructor function deallocates possible contents and MAY free the memory
111 * pointed to by \p memory. Read the documentation of the respective function
112 * pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
113 * particular implementation.
114 *
115 * @param memory a pointer to the object to destruct
116 */
117 typedef void (*cx_destructor_func)(void *memory) __attribute__((__nonnull__));
118
119 /**
120 * Function pointer type for destructor functions.
121 *
122 * A destructor function deallocates possible contents and MAY free the memory
123 * pointed to by \p memory. Read the documentation of the respective function
124 * pointer to learn if a destructor SHALL, MAY, or MUST NOT free the memory in that
125 * particular implementation.
126 *
127 * @param data an optional pointer to custom data
128 * @param memory a pointer to the object to destruct
129 */
130 typedef void (*cx_destructor_func2)(
131 void *data,
132 void *memory
133 ) __attribute__((__nonnull__(2)));
134
135 /**
136 * Structure holding an advanced destructor function and the desired payload.
137 * Invocations of func should use data as first argument.
138 */
139 typedef struct {
140 /**
141 * A pointer to the data that SHALL be used to invoke func.
142 */
143 void *data;
144 /**
145 * A pointer to the function to invoke.
146 */
147 cx_destructor_func2 func;
148 } cx_advanced_destructor;
149
150 /**
151 * Specifies the type of destructor to use.
152 */
153 enum cx_destructor_type {
154 /**
155 * Do not use a destructor function.
156 */
157 CX_DESTRUCTOR_NONE,
158 /**
159 * Use a simple destructor.
160 * @see cx_destructor_func
161 */
162 CX_DESTRUCTOR_SIMPLE,
163 /**
164 * Use an advanced destructor.
165 * @see cx_advanced_destructor
166 */
167 CX_DESTRUCTOR_ADVANCED
168 };
169
170 /**
171 * Allocate \p n bytes of memory.
172 *
173 * @param allocator the allocator
174 * @param n the number of bytes
175 * @return a pointer to the allocated memory
176 */
177 void *cxMalloc(
178 CxAllocator const *allocator,
179 size_t n
180 )
181 __attribute__((__malloc__))
182 __attribute__((__alloc_size__(2)));
183
184 /**
185 * Re-allocate the previously allocated block in \p mem, making the new block \p n bytes long.
186 * This function may return the same pointer that was passed to it, if moving the memory
187 * was not necessary.
188 *
189 * \note Re-allocating a block allocated by a different allocator is undefined.
190 *
191 * @param allocator the allocator
192 * @param mem pointer to the previously allocated block
193 * @param n the new size in bytes
194 * @return a pointer to the re-allocated memory
195 */
196 void *cxRealloc(
197 CxAllocator const *allocator,
198 void *mem,
199 size_t n
200 )
201 __attribute__((__warn_unused_result__))
202 __attribute__((__alloc_size__(3)));
203
204 /**
205 * Re-allocate a previously allocated block and changes the pointer in-place, if necessary.
206 * This function acts like cxRealloc() using the pointer pointed to by \p mem.
207 * On success, the pointer is changed to the new location (in case the
208 *
209 * \note Re-allocating a block allocated by a different allocator is undefined.
210 *
211 * \par Error handling
212 * \c errno will be set, if the underlying realloc function does so.
213 *
214 * @param allocator the allocator
215 * @param mem pointer to the pointer to allocated block
216 * @param n the new size in bytes
217 * @return zero on success, non-zero on failure
218 */
219 int cxReallocate(
220 CxAllocator const *allocator,
221 void **mem,
222 size_t n
223 )
224 __attribute__((__nonnull__));
225
226 /**
227 * Allocate \p nelem elements of \p n bytes each, all initialized to zero.
228 *
229 * @param allocator the allocator
230 * @param nelem the number of elements
231 * @param n the size of each element in bytes
232 * @return a pointer to the allocated memory
233 */
234 void *cxCalloc(
235 CxAllocator const *allocator,
236 size_t nelem,
237 size_t n
238 )
239 __attribute__((__malloc__))
240 __attribute__((__alloc_size__(2, 3)));
241
242 /**
243 * Free a block allocated by this allocator.
244 *
245 * \note Freeing a block of a different allocator is undefined.
246 *
247 * @param allocator the allocator
248 * @param mem a pointer to the block to free
249 */
250 void cxFree(
251 CxAllocator const *allocator,
252 void *mem
253 )
254 __attribute__((__nonnull__));
255
256 #ifdef __cplusplus
257 } /* extern "C" */
258 #endif
259
260 #endif /* UCX_ALLOCATOR_H */

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